LAKE MEMPHREMAGOG

North America

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LAKE MEMPHREMAGOG

A view on the lake

Photo: J.Kalff

A. LOCATION

Quebec, Canada; and Vermont, USA.
44:5'-45:5'N, 72:0'-72:7'W; 208 m above sea level.

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B. DESCRIPTION

Lake Memphremagog is a long (40 km) but narrow (1-3 km) lake, located 130 km to the east of Montreal, Quebec. It is a transboundary lake, receiving 71% of its stream inflow from the Vermont, USA, portion of its catchment, but with 75% of the lake surface area in Quebec, Canada. It is a lake of exceptional, rugged beauty; set in a diverse landscape, hilly and mountainous to the west, but with pastoral, rolling farmland to the east.

The drainage basin of Lake Memphremagog is situated in the physiographic region of the Piedmont. Its early geologic history is tied to the uplift and folding of the Appalachian Mountain chain. The present lake basin was formed about 11,000 B. P. by glacial gouging of a preexisting valley during the final retreat of the Wisconsin glaciation. Following the termination of the Champlain Sea phase, the present lake was formed about 9,500 B. P.

The lake has three distinct basins, a deep Central, and shallower North and South basins. 70% of the lake's watershed is drained by three rivers which enter the lake at the extreme south end and provide the primary input of nutrients into the lake. This has resulted in a distinct nutrient gradient within the lake - the southern end is mesotrophic, while the Central and North basins remain oligotrophic.

The first known settlements were established by the St. Francis Indian community on what they called Lake "Mem-plow-bouque" (large, beautiful expanse of water). The first European settlements were founded in 1793 at Ducansborough (now Newport, Vermont) and in 1794 at Gibraltar Point (now Bolton, Quebec). The Canadian side was largely settled by United Empire Loyalists (settlers who left America after the revolution because they wanted to remain under the British Flag). The lake was popular as a recreation and vacation area in the mid-to-late 1800's, but tourism dropped off sharply after the turn of the century and the area was not subjected to the intensive development pressures and related problems that have affected other river basins in the northeastern United States or southern Quebec. These historical trends are changing as the 1980's brought a new tourism boom and a steady wave of related development to both the American and Canadian portions of the lake basin. The problems associated with increased development have, for the present, been offset by a continuing reduction in crop growing and increased forest regrowth, as well as the installation of tertiary sewage treatment at Newport in 1983 (1, 2, 3).

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C. PHYSICAL DIMENSIONS (1, 2)

Basin	North	Central	South	Total
Surface area [km²]	-	-	-	102
Volume [km³]	-	-	-	1.7
Maximum depth [m]	33 (2)	107	12	107
Mean depth [m]	13	55	8	15.5
Water level	-	-	-	Regulated
Normal range of annual water level fluctuation [m]	-	-	-	0.5
Length of shoreline [km]	-	-	-	121
Residence time [yr]	-	-	-	1.7
Catchment area [km²]	-	-	-	1,764

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D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL

Bathymetric map:
Fig. NAM-48-01.
Names of main islands
Trois Soeurs, Lords, Molson, Longue, Ronde, Province and Whetstone.
Number of outflowing rivers and channels (name):
1 (Magog R.).

D2 CLIMATIC

Climatic data at Sherbrooke*, 1987 (6)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.
Mean temp. [deg C]	-11	-13	-2	7	11	18	19	16	13	6	-1	-6	4
Precipitation [mm]	58	22	54	41	99	124	85	58	93	117	112	62	925

* 23 km from the outflow.

Number of hours of bright sunshine: 1,895 hr yr^-1.
Solar radiation (Montreal Jean Brebeuf*)[MJ m^-2 day^-1]

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.
5.30	8.80	12.51	15.87	9.07	20.25	20.96	17.23	13.45	8.04	4.61	3.92	12.5

* 100 km from the outflow.

Water temperature [deg C](4)

Station South basin, 1985
Depth [m]	Jan	Feb	Mar	Apr	May*1	Jun*2	Jul*3	Aug*4	Sep	Oct	Nov	Dec
S*5	-	-	-	-	9.5	14.4	22.7	22.3	-	-	-	-
1	-	-	-	-	9.3	14.4	21.1	22.6	-	-	-	-
2	-	-	-	-	9.0	14.2	20.6	22.8	-	-	-	-
3	-	-	-	-	8.8	14.2	20.3	23.1	-	-	-	-
4	-	-	-	-	8.7	14.2	20.2	23.5	-	-	-	-
5	-	-	-	-	8.5	14.1	20.1	23.9	-	-	-	-
6	-	-	-	-	8.5	14.1	19.9	24.1	-	-	-	-
7	-	-	-	-	8.4	14.1	16.2	23.9	-	-	-	-
8	-	-	-	-	5.2	13.7	15.6	23.9	-	-	-	-
9	-	-	-	-	5.1	11.2	-	-	-	-	-	-

*1 13 May. *2 12 June. *3 17 July. *4 28 August. *5 Surface.

Station North basin, 1985
Depth [m]	Jan	Feb	Mar	Apr	May*1	Jun*2	Jul*3	Aug*4	Sep	Oct	Nov	Dec
S	-	-	-	-	4.9	13.2	24.1	22.1	-	-	-	-
1	-	-	-	-	4.9	13.1	23.8	22.1	-	-	-	-
2	-	-	-	-	4.8	12.4	22.1	22.1	-	-	-	-
3	-	-	-	-	4.8	12.2	21.3	22.1	-	-	-	-
4	-	-	-	-	4.8	12.2	21.0	22.1	-	-	-	-
5	-	-	-	-	4.8	11.3	20.3	22.1	-	-	-	-
6	-	-	-	-	-	10.0	19.8	22.1	-	-	-	-
10	-	-	-	-	-	6.6	16.4	22.1	-	-	-	-
15	-	-	-	-	-	-	-	16.1	-	-	-	-

*1 14 May. *2 28 May. *3 17 July. *4 28 August.

Station Central basin, 1985
Depth [m]	Jan	Feb	Mar	Apr	May*1	Jun*2	Jul*3	Aug*4	Sep	Oct	Nov	Dec
S	-	-	-	-	8.4	13.8	23.5	20.6	-	-	-	-
1	-	-	-	-	8.3	13.8	21.4	20.8	-	-	-	-
3	-	-	-	-	8.3	13.8	20.2	20.8	-	-	-	-
5	-	-	-	-	8.0	13.7	19.2	20.8	-	-	-	-
7	-	-	-	-	7.5	13.6	18.3	20.5	-	-	-	-
9	-	-	-	-	6.8	12.9	17.1	20.4	-	-	-	-
11	-	-	-	-	6.5	10.9	15.6	19.9	-	-	-	-
13	-	-	-	-	6.2	9.4	13.3	17.8	-	-	-	-
15	-	-	-	-	6.2	9.1	10.5	12.4	-	-	-	-
17	-	-	-	-	6.1	8.4	8.3	9.1	-	-	-	-
19	-	-	-	-	6.0	6.8	7.2	8.8	-	-	-	-

*1 23 May. *2 12 June. *3 17 July. *4 28 August.

Freezing period
South basin: Early December-middle April.
North and central basin: Middle December-middle April.
Mixing type
South basin: Polymictic.
North and central basin: Dimictic.
Notes on water mixing and thermocline formation
Thermally stratified in the Central and North basins, late May-October, with thermocline at 9-11 m depth.

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E. LAKE WATER QUALITY

E1 TRANSPARENCY [m](4)

Station North basin, 1987
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
-	-	-	-	6	5	5.3	4.8	5.8	-	-	-

Station Central basin, 1987
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
-	-	-	-	-	3.9	4.5	4.3	3.5	5.7	-	-

Station South basin, 1987
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
-	-	-	-	2.9	3.6	3.6	-	4.8	-	-	-

E2 pH

Station Central basin, 1987
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
S*	-	-	-	-	-	-	-	8.3	-	-	-	-

* Surfaca.

Station Newport Bay, 1988
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
S	-	-	-	-	-	6.7	-	7.1	-	-	-	-

E4 DO [mg l^-1](18)

Station Central Basin, 1985
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
1	-	-	-	-	12.5	10.8	9.5	9.3	8.8	-	-	-
3	-	-	-	-	12.6	10.8	9.7	9.3	8.9	-	-	-
5	-	-	-	-	12.6	10.8	9.9	9.4	8.9	-	-	-
7	-	-	-	-	12.7	10.8	10.0	9.5	8.8	-	-	-
9	-	-	-	-	12.6	10.8	9.7	9.5	8.7	-	-	-
11	-	-	-	-	12.5	10.8	9.5	9.5	8.0	-	-	-
13	-	-	-	-	12.4	10.8	9.1	8.8	7.3	-	-	-
15	-	-	-	-	12.3	10.8	9.1	8.2	7.5	-	-	-
17	-	-	-	-	12.3	10.9	9.5	7.8	8.4	-	-	-
19	-	-	-	-	12.3	10.9	9.7	8.1	8.7	-	-	-
21	-	-	-	-	12.3	11	10.2	8.8	9.3	-	-	-

E6 CHLOROPHYLL CONCENTRATION [micro l^-1](4)

Station North Basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	3.0	4.2	2.5	2.6	3.3	-	-	-

*1 Monthly mean. *2 Integrated.

Station Central Basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	4.0	3.9	2.1	3.6	2.9	-	-	-

Station South Basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	4.7	6.0	4.2	3.6	2.3	-	-	-

E7 NITROGEN CONCENTRATION (4)

Total-N [mg l^-1]

Station North basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	0.60	0.35	0.28	0.30	0.23	-	-	-

*1 Monthly mean. *2 Integrated.

Station Central basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	0.65	0.42	0.31	0.23	0.39	-	-	-

Station South basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	0.46	0.42	0.36	0.29	0.27	-	-	-

E8 PHOSPHORUS CONCENTRATION (4)

Total-P [mg l^-1]

Station North basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	.013	.013	.011	.010	.009	-	-	-

*1 Monthly mean. *2 Integrated.

Station Central basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	.017	.013	.012	.011	.011	-	-	-

Station South basin, 1987*1
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
5*2	-	-	-	-	.016	.016	.016	.015	.014	-	-	-

E10 PAST TRENDS: Fig. NAM-48-02 and 03.

^-1

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F. BIOLOGICAL FEATURES

All stations combined, 1973-1987

F1 FLORA

Submerged macrophytes (7)
Cabomba caroliniana, Elodea canadensis, E. septangular, Heteranthera dubia, Isoetes sp., Myriophyllum spicatum, Najas sp., Potamogeton richardsonii, P. praelongus, Vallisneria americana, Nitella sp.
Phytoplankton (14)
South basin: Diatoma tenue var. elongatum, Oscillatoria redekei, Ceratium hirundinella, Rhodomonas minuta, Melosira italica, Cryptomonas reflexa, Stephanodiscus astraea, S. nantzschii, Asterionella formosa, Fragilaria crotonensis, Uroglena volvox, Anabaena flos-aqae, Gleococcus schraeteri, Coelosphaerium naegelianum.
North basin: Diatoma tenue, Oscillatoria redekei, Fragilaria crotonensis, Rhizosolenia eriensis, R. minuta, Botryococcus braunii, Cyclotella bodanika, C. hirundinella, Synedra ulna var. danica, Chrysochromulina parva, Gleococcus schroeteria, Coelosphaerium naegelianum.

F2 FAUNA

Zooplankton (12, 16, 17)
Cyclops bicuspidatus thomasi, C. vernalis, Mesocyclops edax, Diaptomus sicilis, D. minutus, Tropocyclops prasinus mexicanus, Epischura lacustris, Senecella calanoides, Daphnia galeata, Bosmina longirostris, B. coregoni, Chydorus sphaericus, Holopedium gibberum, Ceriodaphnia quadrangula, Diaphanosoma leuchtenbergianum, Keratella sp., Monostyla sp., Polyarthra sp.
Benthos (8, 12)
Chironomus anthracinus, Chaoborus punctipennis, Tanytarsus spp., Procladius spp., Phaenospectra sp., Microspectra sp., Pontoporeia hoyi, Amnicola sphaerium, Fossaria, Helisoma.
Fish (9)
Hybognathus nuchalis, Notemigonus crysoleucas, Notropis volucellus, Pimephales notatus, Etheostoma nigrum, Perca flavescens, Fundulus diaphanus, Lepomis gibbosus, Micropterus dolomieu, Semotilus corporalis, Catostomus commersoni, Osmerus mordax.
Supplementary notes on the biota (8, 9)
The nutrient gradient along the axis of the lake influences the abundance and distribution of organisms. Biomass of fish species is about three times greater in the more productive southern end. Phytoplankton and benthos biomass and production too are greater in the south.

F3 PRIMARY PRODUCTION RATE (10)

Phytoplankton
Net C14 Production rate [g C m^-2 day^-1]

Station North basin, November 1972-October 1973
1973											1972	Ann.
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	total
0.1	0	0.1	0.3	0.8	0.9	0.7	0.7	1.0	0.5	0.3	0.2	175*

Station Central basin, November 1972-October 1973
1973											1972	Ann.
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	total
-	-	-	-	0.6	1.0	0.7	1.0	-	-	-	-	-

Station South basin, November 1972-October 1973
1973											1972	Ann.
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	total
0.1	0.1	0.3	0.7	0.7	0.7	1.3	1.1	1.5	0.7	0.2	0.1	219*

* 1972-1973.

F4 BIOMASS (9)

Benthos [g (dry wt.) m^-2]
1972-1973
South basin: 3.30 ±0.25.
North basin: 1.19 ±0.06.

F7 NOTES ON THE REMARKABLE CHANGES OF BIOTA IN THE LAKE IN RECENT YEARS

None.

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G. SOCIO-ECONOMIC CONDITIONS

G1 LAND USE IN THE CATCHMENT AREA (1, 2)

Station 1981
	Area [km²]	[%]
Natural landscape
- Woody vegetation	1,300	74
- Herbaceous vegetation	88	5
- Swamp	36	2
Agricultural land
- Crop field	240	14
Residential area	80	5
Total	1,744	100

Types of important forest vegetation:
Maple, beech, birch, spruce, fir.
Types of important herbaceous vegetation:
Abandoned pasture, hay.
Main kinds of crops and/or cropping systems:
Hay, maize.
Levels of fertilizer application on crop fields
Light (manure application).
Trends of change in land use in recent years (2)
Historically, economy based on natural resources. Now manufacturing is playing a more significant role. 37% decline in natural resource industries (agriculture, forestry) from 1960 to 1970. In the 1980's, 10% of woodland harvested annually.

G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE (2)

Station 1974 U.S. portion of the catchment area (Orleans County) only.
	Gross product during the year (= US$1.00)	Percentage of persons engaged	No. of establishments	Main products or major industries
Primary industry	24 mill.	16	666
- Crop production				Corn, hay
- Animal husbandry				Dairy products
- Fisheries
Secondary industry
- Manufacturing & construction	N.A.	32	27	Machinery, clothing
Tertiary industry	N.A.	40		Service, transport, etc.
(Unemployed)		12

Numbers of domestic animals in the catchment area
Cattle 25,000, others unknown.

G3 POPULATION IN THE CATCHMENT AREA (2)

Station 1975
	Population* density [km^-2]	Population (population)	Main cities
Rural	19,702
Total	19,702	11.2	Newport, Derby

* Included - 18,702 in U.S. and 1,000 in Canada.

Supplementary notes (1)
Seasonal population is +20,000, and rapidly growing. More than 1,500 vacation cottages line the shores of the lake.

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H. LAKE UTILIZATION

H1 LAKE UTILIZATION

Source of water, sightseeing and tourism (no. of visitors in 1975: 20,000) and recreation (swimming, sport-fishing, yachting).

H2 THE LAKE AS WATER RESOURCE (2)

Station 1974
	Use rate [m³ sec^-1]
Domestic	1
Industrial	34

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I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS

I1 ENHANCED SILTATION

Extent of damage:
Not serious.
Supplementary notes
Excessive erosion and sedimentation on cropland on steep slopes-on Vermont rivers. Streambank erosion due to livestock and soil erosion due to poor logging practices. Offset by gradual reduction in cropland and increases in pasture and forest.

I2 TOXIC CONTAMINATION

Present status:
Detected but not serious.
Main contaminants, their concentration and sources

Station North basin, 1988
Name of contaminants	Concentration [ppm] in bottom mud*
Zn	198
Mn	533
Ni	109
Cu	45
Pb	117

* Dry weight basis.

Supplementary notes (11)
Metal levels not highly variable throughout the lake.

I3 EUTROPHICATION

Nitrogen and phosphorus loadings to the lake [t yr^-1](13)

Station 1972, 1987
Sources	Domestic 1987	River loading 1972	Natural recip. 1972	Total
T-P	1	21	7	29

Supplementary notes (13)
Eutrophication has only been a problem in the extreme south end of the lake, while north and central basins are oligotrophic. However, a new sewage treatment system that went into operation in 1983 reduced the T-P loadings (from the town of Newport) from 20 t yr^-1 to <1 t yr^-1.

I4 ACIDIFICATION

Extent of damage:
None.

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J. WASTEWATER TREATMENTS

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA

J3 SANITARY FACILITIES AND SEWERAGE

Percentage of municipal population in the catchment area provided with

Percentage of rural population with adequate sanitary facilities (on-site
Municipal wastewater treatment systems
No. of tertiary treatment systems: 3 (P removal).
No. of secondary treatment systems: 3.
No. of industrial wastewater treatment systems: 2.

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K. IMPROVEMENT WORKS IN THE LAKE (Q)

None.

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L. DEVELOPMENT PLANS (Q)

Increasing recreational development and condominium construction.

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M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS

M1 NATIONAL AND LOCAL LAWS CONCERNED

Names of the laws (the year of legislation)
1. The level at which Lake Memphremagog should be maintained. Dam on outflow (1935).
Responsible authorities
1. Environment Canada, U.S. Dept. of the Army/Corps of Engineers, Quebec
2. Dept. of the Environment
Main items of control
1. Lake level

M2 INSTITUTIONAL MEASURES

Memphremagog Conservation Inc., Quebec (employs students in clean-up work and public education).

M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES

Limnology Research Centre, McGill University, Montreal, Quebec

N. SOURCES OF DATA

(Q1) Questionnaire filled by Dr. J. Kalff, Limnology Research Centre, McGill University, Montreal, Canada.

Memphremagog Conservation Inc. (1982) Environmental Land Use Guide of the Lake Memphremagog Watershed.
New England River Basins Commission (1981) Lake Memphremagog-St. Francis River Basin Overview.
Carlson, R. E., Kalff, J. & Leggett, W. C. (1979) The phosphorus and nitrogen budgets of Lake Memphremagog; with a predictive model of its nutrient content following sewage removal.
Limnology Research Centre (1972-1988) Lake Memphremagog Data Collection.
Rasmussen, J. Personal communication.
Environment Canada (1987) Meteorological reports.
(6a) Canadian Climate Normals, 1951-1980. Environment Canada, Atmospheric Environment Service.
Downing, J. A. & Anderson, M. R. (1985) Estimating the standing biomass of aquatic macrophytes. Can. J. Fish. Aquat. Sci., 42(12): 1860-1869.
Dermott, R. M., Kalff, J., Leggett, W. C. & Spence, J. (1977) Production of Chironomus, Procladius and Chaoborus at different levels of phytoplankton biomass in Lake Memphremagog, Quebec-Vermont. Can. J. Fish Aquat. Sci., 34(11): 2001-2007.
Gascon, D. & Leggett, W. C. (1977) Distribution, abundance and resource utilization of littoral zone fishes in response to a nutrient/production gradient in Lake Memphremagog. J. Fish. Res. Bd., 34: 1105-1117.
Ross, P. E. & Kalff, J. (1975) Phytoplankton production in Lake Memphremagog, Quebec (Canada) - Vermont (USA). Verh. Int. Ver. Limn., 19: 760-769.
Rowan, D., McGill Univ. Personal communication.
Morse, J. W. & Flanders, P. H. (1971) Primary Productivity Study of Three Vermont Lakes. State of Vermont Agency of Conservation.
Kalff, J. & Lawson, A. (1988) The Capacity of Lake Memphremagog for Further Development. Limnology Research Centre, McGill University.
Watson, S. (1979) Phytoplankton dynamics in Lake Memphremagog and their relationship to trophic level. M. Sc. Thesis, McGill University, Montreal.
Chambers, P. & Kalff, J. (1985) Depth distribution and biomass of submerged aquatic macrophyte communities in relation to Secchi depth. Can. J. Fish. Aquat. Sci., 42: 701-709.
Sarafian, V. (1984) Life cycles, biomass and production of copepods in Lake Memphremagog. M. Sc. Thesis, Concordia University, Montreal.
Shoenert, R. A. & Peters, R. H. Cladoceran abundance along the trophic gradient of Lake Memphremagog. Internal report. McGill University, Montreal.
Marshall, T. Personal communication.

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International Lake Environment Committee

Promoting Sustainable Management of the World's Lakes and Reservoirs